The 54-year-old singer is celebrating 10 years since she won her own battle with the disease and Sheryl believes 45-year-old Shannen's decision to go public will encourage other women to be more proactive about getting themselves checked.

Speaking at the BlogHer conference in Los Angeles, she said: ''I think that [talking about cancer] takes the fear out of it. I mean, it is a scary thing, but one of the problems we have with breast cancer in general is getting women to go and get a mammography. A lot of us who are moms are too busy, or we don't really want to know. I think a lot of women really kind of don't want to know. In some instances, we're poorly insured or uninsured. And until we find a cure, early detection is our cure. The statistic of the cure rate at five years is 100 percent if it's detected early.''

''So I love women who are coming out and saying, 'This is what I've done. I've been proactive and I'm celebrating my life. It's just really hard to imagine that 30 years ago, no one had spoken about having breast cancer until Betty Ford. When she came out and announced [she had it], it was very taboo and shocking. And now we can talk about it and it's a part of our everyday life. Knowledge is power.

''[I'm cancer free] all because of a mammography. I had a little calcification that showed up, or maybe a couple on my mammography, and they said come back in six months. That was even before the 3D. Now we have the Genius 3D machine, which can detect things 15 months earlier.''

Sheryl, who has sons Wyatt, nine, and Levi, six, also called her diagnosis a ''game changer'', saying it helped her to see what was really important.

She said: ''My diagnosis was a real game changer. At that point, I was 44, and I was the picture of great health.

''I've had a lot of people say, 'Yeah, these things help you redefine your life,' but for me, I really refined my life. I began to really hack away at the things that were not important anymore and the things that were energy sucking. I learned how to say no.''